How to use
- Paste your earlier version into Original.
- Paste your revised version into Changed.
- Set Highlight to Word, Character, or Line only.
- Click Compare if live comparison is paused for large inputs.
- Click Copy diff to copy the changes as a unified diff.
Examples
Review a config update
Original: host=localhost port=8080 debug=false Changed: host=localhost port=9090 debug=true log=info
--- original +++ changed @@ -1,3 +1,4 @@ host=localhost -port=8080 -debug=false +port=9090 +debug=true +log=info
Ignore indentation and check a timeout change
Original:
def request_settings():
timeout = 30
return timeout
Changed:
def request_settings():
timeout = 45
return timeout
--- original +++ changed @@ -1,3 +1,3 @@ def request_settings(): - timeout = 30 + timeout = 45 return timeout
FAQ
Are my texts uploaded or saved?
Comparison runs in your browser; your texts are not uploaded or saved by the tool. Only option settings are stored locally. Share link includes both texts in the URL, compressed but not encrypted, so anyone with the link can read them.
Can I compare PDF, Word, Excel, or image files?
Those formats are not supported. Upload UTF-8 text files, such as code, config files, CSV, or logs; binary files and invalid UTF-8 are rejected.
How do I compare JSON files?
Format both documents with JSON Formatter first to make line-by-line changes easier to read. This tool compares text, not JSON structure, so a change in key order still counts as a difference.
What is the file size limit?
Each text or file is limited to 20 MB, with a warning above 5 MB per side. Live comparison pauses when the combined inputs exceed 204,800 characters. Comparisons that take longer than 15 seconds are stopped; compare smaller sections if that happens.
Does the diff checker detect moved lines?
Moved lines appear as a removal and an addition. The tool does not detect moves or offer three-way merging.